joe? the treasury department isn't talking about contingency plans but a group called the bipartisan policy center did its own analysis. between tuesday and the end of august, the's the bring in $172.4 billion in taxes and other revenue but will owe more than $306 billion. let's say you use the cash to pay interest on treasury securities, social security, medicaid and medicare, defense vendors and unemployment insurance. you won't have anything left to pay active-duty military, federal salaries and benefits, the departments of education, labor, justice, energy, e.p.a., or anything else. >> choicies then have to be made and it's a sophie's choice, right. who do you save? who do you pay? >> reporter: but experts told us that neither treas nor the white house has the legal authority to make those decisions. the power of the purse belongs to congress alone and it's hard to imagine they'd have an easier time agreeing on what bills to pay than they have on the debt sealing. >> we're going to pay